The present invention relates to methods of using separating methane from a mixture containing methane and nitrogen, and, in particular, to methods of separating methane from a mixture containing methane and nitrogen using microchannels and ionic liquid absorbents.
Gas-liquid reaction systems are known. See, e.g., Matthew W. Losey et al., “Microfabricated Multiphase Packed-Bed Reactors: Characterization of Mass Transfer and Reactions,” Ind. Eng. Chem. Res. 2001, 40, 2555-2562. Anthony et al. (“Solubilities and Thermodynamic Properties of Gases in the Ionic Liquid 1-n-Butyl-3-methylimidazolium Hexafluorophosphate”, Anthony, J., Maginn, E., and Brennecke, J., J. Phys. Chem B 2002, 106, 7315-7320) describe one example of an ionic liquid that suggests a single stage separation of methane and nitrogen are possible. U.S. Pat. No. 6,579,343, which is incorporated by reference, discusses the use of ionic liquids for gas separations.
The use of wicks or capillary structures for thin film is described in U.S. Pat. Nos. 6,875,247 and 7,051,540, which are incorporated by reference. Surface features for multiphase processing are described in U.S. Patent Application Publication No. 2007/0085227, which is incorporated by reference.
Foam flow is discussed in three articles by Stemmet et al.: Stemmet, C. P., Jongmans, J. N., van der Schaaf, J., Kuster, B. F. M., Schouten, J. C., “Hydrodynamics of gas-liquid counter-current flow in solid foam packings,” Chemical Engineering Science, 60, 6422-6429, 2005; Stemmet, C. P., van der Schaaf, J., Kuster, B. F. M., Schouten, J. C., “Solid Foam Packings for Multiphase Reactors—Modelling of Liquid Holdup and Mass Transfer,” Trans. ChemE, Part A, Chemical Engineering Research and Design, 84 (A12), 1134-1141, 2006; and Stemmet, C. P., Meeuwse, M., van der Schaaf, J., Kuster, B. F. M., Schouten, J. C., “Gas-liquid mass transfer and axial dispersion in solid foam packings,” Chemical Engineering Science, 62, 5444-5450, 2007.